A battery energy storage system generally includes a plurality of battery modules connected in series with each other, and each battery module consists of one battery cell or more battery cells connected in parallel or in series. For so many batteries, it is required battery management system can monitor battery performance parameters in real time, control charging and discharging of the battery modules, manage battery equalization, thermal management, battery status estimation, online diagnosis, early warning and so on. At present, a number of battery energy storage systems use a battery sampling integrated chip to achieve functions parameter like voltage acquisition for a single battery cell, and the battery sampling integrated chip needs to be woke up before the entire battery energy storage system is in normal operation. The battery energy storage system includes a power low-voltage side and a power high-voltage side, the battery sampling integrated chip belongs to the power high-voltage side, and a microcontroller unit (Microcontroller Unit, MCU) belongs to the power low-voltage side, data is transmitted between the battery sampling integrated chip and MCU by an isolation chip, a portion of the isolation chip belongs to the power high-voltage side, the other portion of the isolation chip belongs to the power low-voltage side, and both the portions of the isolation chip should be powered to achieve normal operation, however, for the power high-voltage side cannot be powered before the entire system is in normal operation, in order to wake up the battery sampling integrated chip, the existing solution is to take/get electricity from the power low-voltage side and then supply battery sampling integrated chip at the power high-voltage side by an isolation power source.
During implementing the present application, it is found that at least the following problems exist in the prior arts:
It should be noted that Isolation power source is costly, and it also may cause an electro-magnetic compatibility (EMC) problem due to characteristics of the isolation power source itself.